Safety-valve for pneumatic tires.



I w.1. YOUNG,` SAFETY VALVE FOR PNE-UMATIC TIRES. APPLICATION FILED FEB.I9 |914.

Wirneses. InvenTor.

Lm'fww/l. william. Young,

. b @MKM y AHys are WILLIAM J. YOUNG', 0F MINETTO, NEW YORK.

SAFETY-VALVE FOR PNEUMTIC TIRES.

Specification of Letters Patent.

Patented Mar. 5, 1918..

Application led February 19, 1914. Serial No. 819,811.

To all whomz't may concern:

Be it known that I, WmLrAM J. Yonne, a citizen of the United States,residin at Minette, county of Oswego, State of ew York, have invented anImprovement in Safety-Valves for Pneumatic Tires, of which the followingdescription, in connection with the accompanying drawing, is aspecilication, like characters on the drawing representing like parts.

This invention relates to safety valves for pneumatic tires which aredesigned to relieve the pressure within the tire when the latter exceedsa redetermined amount, and it has for its o ject to provide a novelsafety valve of this type, all as will be more fully hereinafterdescribed and then pointed out in the appended claim.

The drawings show a sectional View illustrating a selected embodiment ofmy invention from which the principle thereof will be readily seen.

1 designates the ordinary valve stem of a pneumatic tire having theusual valve 2 therein provided with a valve stem 3, said valve beingnormally seated by the spring 4. These are the parts which are of commonconstruction and form no part of my present invention.

In accordance with my invention I provide a member 5 which is adapted tobe screwed to the screw-threaded end 6 of the valve stem 1, said memberhaving at its inner end a guiding head 7 which lits over the valve stemand which coperates with the screw-threaded portion to hold the member 5rmly in place. This member 5 is provided with an outer chamber 8 whichcommunicates with the bore of the valve stem 1 through a passageway 9and this passageway is normally closed by a balanced safety valve 10which is held a ainst aseat 11 by means of a spring 12. T e spring isshown as backed against an adjustable plate 13 that is screw-threadedinto the chamber 8 and by means of which the tension of the spring maybe controlled. The outer end of the casing 5 is closed by a removablecap 14 which is provided with a stem 15 constituting an auxiliary valvechamber. -Within this stem a valve seat member 16 is secured with whichcoperates a safety valve 17 that is held to its seat by a spring 18.This spring 18 is backed against a cap 19 that is adjustably secured tothe stem 15, said cap being provided with the port 20. The

plate 18 is also provided with a port 21 for.

the escape of air.

The safety valve 10 is provided With a central aperture 22 having avalve seat 23 at its inner end, which valve seat is normally closed byan inwardly-opening check valve 24 that is held to its seat by a spring25 arranged to engage ay collar 26 on the end of the stem 27 of saidvalve 24. This valve 24 is also provided with a projection 28 of such alength that when the casing 5 is in proper position and the safety valve10 is closed, this projection will engage the end of the stem 3 of theusual valve 2 and open said valve away from its seat. Therefore, when myattachment is applied to a valve stem, the valve 2 with which the valvestem l is ordinarily supplied is open. The air in the tire, however, isprevented from escaping by means of the valves 24 and 10, the valve 24being held to its seat by air pressure and the spring 27, while thevalve 10 which is an outwardly-opening valve is held to its seat by thespring 12. This spring l2 will have suflicient strength to hold thevalve 10 seated against the ordinary pressure in the tire.

If, however, the pressure in the tire increases either permanently ormomentarily beyond the safety point by reason of the air in the tirebecoming heated or because of the wheel running over obstructions, suchincreased pressure will open the valve 10 and allow a certain amount ofairv to pass into the chamber 8. This chamber 8 may be made of anysuitable size and if the amount of air which thus escapes into thechamber 8 is sul'iicient to relieve the excessive pressure in the tire,then the valve 10 will automatically seat itself again. If, however, theamount of air which escapes from the tire is greater than that requiredto lill the i tension of the springs 12 and 18 can be adjusted so thatthe safety valves will o en when any predetermined pressure is reac edin the pneumatic tire, and the presence of these valves operates toprevent blow-outs from occurring.

The chamber 8 is in the nature of a storage chamber as it receives andstores up a certain vcliune ef air when any air escapes from the tirethrough the valve l0: Aiter the pressure in the tire has been relievedby the eseape et air into the chamber 8, tbepressnre in said chamberwill be substantially equal te that ci the increased. geressure in thetire, and this pressure will remain in the chamber 8 so long as thepressure in the tire does not decrease materially below its normalamount. lf, however, the tire pressure dces decrease, then the greaterpressure in tbe chamber 8 will open tbe valve 2e, thus allowing some ofthe an' in the chamber 8 to pass back inte the tire again.

it will be noted that the valve l0 is formed with the dange 3l by meansci which the valve is practically balanced, thus malrins1 it meresensitive.

Having described my invention, what l claim as new and desire to secureby Letters Patent-is e u In a device of the class described, thecennbination with the vaive stein of a pneumatic tire, of akcasingsecured theretcand provided with a chamber, said casing having anopening forming a communication between said chamber and the air passageci aesacve said valve stem, theouter end of said opena ing constitutinga valve seat, an outwardlycpening valve engaging said seat and having anextension which is received in said open ing, said valve having an axialpassage therethrough and the lower end of said exneck, anoutwardly-opening valve in the neck of the cap, an apertnred capscrewthreaded to the neck of the first-named cap, and a spring coninedbetween said second cap and said second outwardly-opening valve.

ln testimony whereof, l have signed my naine to this specification, inthe presence of two subscribing witnesses.

WILLIAM J. YOUNG. Witnesses:

S. F. KEDY, CEAS. H. YOUNG.

